Digital and analog data transmissions are prevalent in today's society. Digital and analog data transmission occurs in telephone communication, Internet use, cable television, and a host of other mediums. As society becomes more and more reliant on data transmission, it becomes more and more necessary to verify the sent data corresponds to the received data.
While it is important to verify data, generically, sometimes data streams receive substitutions of portions of the stream. By way of non-limiting example, it is known to insert advertisement copy, including digital advertisement copy, into analog and/or digital TV programs. Generally, when inserting the advertisement copy into a TV program, the inserted advertisement is broadcast instead of or over an original advertisement. As is well-known, national broadcasters, such as, NBC, insert national advertisements during the broadcast of a TV program for users to view. The national broadcaster allows certain of these national advertisements to be replaced by local advertisements. Generally, the replaceable national advertisements are preceded by a queue signal that indicates that a local advertisement can preempt the following national advertisement.
If the local TV system has a local advertisement that has been sold and is scheduled for presentation to the local TV subscribers, the occurrence of a queue-signal triggers the fetching of a designated local advertisement copy from advertisement storage. The fetched local advertisement copy replaces the national advertisement in the broadcast for viewing by local TV subscribers. After broadcasting the local advertisement, the local TV system resumes broadcasting the national broadcast.
Thus, especially when the data stream is preempted or overwritten, it would be desirous to provide apparatuses and methods to verify data streams and transmission.